Like nature, the Apple rumor mill abhors a vacuum, and for much of this month it has been filled with talk of “the Brick.”

What is the Brick? The question was first posed the day after Steve Jobs’ “Let’s Rock” keynote address by Cleve Nettles on the Apple blog 9 to 5 Mac. He wrote that a tipster with “a solid track record” told him that the mid-October introduction of a new line of MacBooks (see here) is “all about the Brick.”

“What does ‘The Brick’ mean?” Nettles asked his readers. “Can anyone out there help us out?” (link)

Readers were happy to oblige. Hundreds of messages, dozens of blog postings, and at least two reader polls later, no definitive answers have emerged. Speculation reached a fever pitch this weekend after The Unofficial Apple Weblog (TUAW) reported that Apple had e-mailed resellers with instructions to remove and destroy all Apple TV displays and literature by 5 p.m. Sept. 30, when a webcast “kick off” was supposedly scheduled. Could the Brick be the long-awaited arrival of Apple TV, Take 3?

The Sept. 30 deadline, it turns out, is the anniversary of the debut of those Apple TV store displays, which suggests that the company may simply be destroying some outdated print material containing screen shots whose permissions have run out. (link)

But that hasn’t slowed the flood of ideas about what Steve Jobs might have up his sleeve next. As is often the case with Apple watchers, the speculation says more about their needs and fantasies than Apple’s (AAPL) product plans.

So what’s on their wish list? A sampling of what some have suggested the Brick might be:

An Apple TV with a built-in Blu-Ray disk, TV receiver, digital TV recorder and its own App store (link)A new Apple-branded gaming system (link)A Time Capsule with “smarts” that functions as an iTunes server (link)A redesigned and much more powerful Mac Mini (link)The announcement that Apple has aquired TiVo (TIVO) and is discontinuing the Apple TV (link)A tablet-sized Mac with a touch-screen keyboard (link)A low-cost MacBook to compete in the sub-notebook market (link)A wireless USB hub that that links keyboards, mice, DVD drives, networking, hard drives, new displays (link)Nothing brick-shaped, but rather a product or group of products sexy enough to “smash” Microsoft’s (MSFT) Windows once and for all (link)My favorite reader comment, posted by “cardiomac” on TUAW in response to a suggestion that the Apple TV was “not meant to be a computer,” borrows from the “The Lovesong of J. Alfred Prufrock“:

No! I am not a computer, nor was meant to be;Am an attendant lord, one that will doTo swell a progress, start a scene or two,Advise the prince; no doubt, an easy tool,Deferential, glad to be of use,Politic, cautious, and meticulous;Full of high sentence, but a bit obtuse;At times, indeed, almost ridiculous—Almost, at times, the Fool. (link)